On January 21, 2024, a meteor disintegrated over Germany near Berlin. That's not so unusual, but NASA was able to give warning of its approach 95 minutes before impact thanks to the space agency's international planetary defense network.
Most people aren't aware of it, but the Earth is constantly bombarded with meteors every single day. According to NASA, about 44 tonnes of meteors hit the Earth daily. Over 95% of these burn up in the Earth's atmosphere, though about 17,000 reach the surface per year, of which 75% vanish into the ocean.
That may seem to be of interest only to rockhounds and trivia buffs, but NASA and other organizations are very interested as well – and not just from a scientific point of view. While most of these meteors are the size of dust motes, they come in bigger varieties as well. If they are large enough they can cause damage on impact or they may explode in the air, as happened over Chelyabinsk, Russia in 2013.
If they're large enough, getting up into the asteroid range, they can strike with the force of a hydrogen bomb or even cause a mass extinction event like the one that caused the dinosaurs to cash in their chips.
Fortunately, the larger and more dangerous these objects are, the rarer they are. That means that if something really nasty is headed our way, it might be possible to deflect them into a safe orbit over a period of years or even decades. Even with the smaller variety, getting some warning can help to avoid injuries, like the victims of flying glass caused by the Chelyabinsk event.
In the most recent encounter, NASA's Scout impact assessment system was able to track a 3-ft (1-m) diameter body called asteroid 2024 BX1, which burned up on January 21 at 1:32 CET about 37 miles (60 km) outside of Berlin. Its disintegration produced a fireball that could be seen as far away as the Czech Republic.
Though NASA is only tasked by the US Congress with tracking objects larger than 140 m (460 ft), the Scout system can also handle much smaller objects and has done so eight times now with very little fanfare. These incidents allow the space agency to demonstrate how fast the system can compute trajectories and provide impact alerts.
In the case of asteroid 2024 BX1, it was spotted less than three hours before impact by Krisztián Sárneczky at the Piszkéstető Mountain Station of the Konkoly Observatory near Budapest, Hungary. The data was sent to the International Astronomical Union's Minor Planet Center and automatically updated to the center's Near-Earth Object Confirmation Page.
This allowed other astronomers to access and use the information, along with Scout, which is a computer system developed by the Center for Near Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. This calculated the trajectory of the object and passed on its results to NASA's Planetary Defense Coordination Office (PDCO) in Washington, DC.
From only three observations, Scout identified a possible impact and requested more information, which European astronomers quickly provided. This allowed Scout to confirm the probable impact only 70 minutes after the object was discovered and allowed for over an hour and a half's warning.
Source: NASA
